This invention relates to an ice-cream cup.
Some manufacturers several decades ago marketed an ice-cream cup called "push-up", which is made of cardboard and which has a slidable bottom supported and pushed up by a downward bar. It was found unpleasantly that melted ice-cream leaks and drips down along the inner wall of the "push-up".
U.S. Pat. No. 3,342,609 of H. Bank and P. Carter suggested a container which has a slidable bottom and a downward push-up bar. U.S. Pat. No. 654,031 of W. Smith introduced a tobacco-holder with a slidable bottom which has an upstanding peripheral flange to improve mechanical fitting and to prevent leaking. It is an obvious suggestion to combine these two inventions to form an ice-cream cup which has a slidable bottom with a downward bar and with an upstanding peripheral flange, to better solve the leaking and dripping problem and to offer better mechanical fitting. Such a suggested design for ice-cream cup may work very well when the cup is made of some stiff materials such as cardboard. The suggested cup, however, has insolvable leaking and mechanical fitting problems, when the cup is made of some soft materials such as soft thin plastic. When comsumers consume the semi-liquid ice-cream emerging from the upper edge of the cup, a horizontal force is usually applied in addition to a vertical force and such a horizontal force forms a big bending torque around the axis which goes through the center of the slidable bottom and which is perpendicular to the horizontal force. The fitting between the wall and the bottom of the suggested soft wall cup is basically an unstable mechanical equilibrium when the big bending torque is applied. The wall and the upstanding flange separate from each other and melt ice-cream leaks and drips down. The result is that soft plastic cannot be used for such a suggested design of ice-cream cup.
This invention solves the above mentioned leaking and mechanical fitting problems, making soft materials such as soft thin plastic applicable to bottom slidable ice-cream cup. The cup of this invention has a special slidable bottom which has an upstanding fitting rim, a horizontally stretched buffer, and a vertically stretched buffer. The fitting rim and the two buffers offer stable mechanical equilibrium under a bending torque. The fitting rim and the two buffers form a trough to store melt ice-cream.